Problem/Justification
TrueNAS (via ZFS on Linux) gives implicit privileges to file owners including ability to change ownership and ACLs. On an enterprise file share it is usually undesirable for users to be able to change file ownership and permissions just because they created the file, whether maliciously, or accidentally for example with cp -p.
Illumos implemented a way to disable implicit permissions via a zfs option aclimplicit: Feature #15338: ZFS implicit owner rights should be configurable - illumos gate - illumos
Request is to implement the same on TrueNAS.
Impact
Compatibility with Windows and NFSv4 specification that requires users to have write_ownership privilege (e.g. via Full Control) to change ownership.
Compatibility with Windows that requires users to have write_acl privilege explicitly (e.g. via Full Control) to change ACL (when an Owner Rights ACL is applied on Windows vs. all the time with aclimplicit=off).
Avoid accidental or malicious ownership and ACL changes.
In the absence of rigorous logging, an adversary could presently create a malicious file and then chown it to an innocent user, to appear like the innocent user created the malicious file (works over NFSv4).
User Story
zfs set aclimplicit=off tank
Web GUI option on dataset.